So my sister sent me this picture of her pool filters that she changed out recently. Besides making me go, “Ewwww!” it made me ponder how one knows just when it’s time to change out the cartridges versus just clean them. As with any type of filter there is no hard and fast rule that says your filter will last X amount of time. It depends on the application, the quality of water passing through, quality of cartridge, usage rate, etc. There are definite indicators, though, that it’s time to change out the cartridges for new ones.
- Broken bands – If your filter cartridges have bands and several of them are broken, it is time to change the filter. Bands play an important role in keeping the pleats from flattening out when under pressure, allowing for the optimal surface area. As an aside, I’ve talked to some contractors who say they cut the bands to make cleaning easier. DON’T DO THIS!
- Fabric is frayed – Cartridges are generally made of polyester media which, over time, will wear out from repeated torture from suspended particles and chemicals that the pump is forcing through it. The material will start to look ‘hairy’ or even develop visible holes, allowing debris to pass through and back into your pool. In the words of comedian Bill Engvall, ‘There’s your sign!”
- Pleats are flattening – Over time the integrity, or rigidity, of the material diminishes and the pleats begin to flatten. For the same reasons as mentioned above, this is not ideal.
- Cracked endcaps - Over time the endcaps of a filter can become brittle and weaker from constant pressure and chemical exposure. Due to advances in manufacturing, the media will most often wear out far before the endcaps crack.
- Flow doesn’t change – In our video How to Change Your Filter Cartridge, we discuss the differential pressure gauge and how to determine when your filter needs cleaning. When the pressure gauge reads 10-12 psi above that recorded when new filters are installed it’s time to clean your filter cartridges. When the pressure reading remains the same or only slightly decreases after cleaning them, it’s likely time to replace the cartridges as the dirt and oils have embedded themselves within the fabric of the cartridge. At this stage the cartridges will no longer appear clean either, even after cleaning.
Cartridge selection is important in extending the time between filter change-outs. FILBUR Manufacturing uses only REEMAY Filtration Fabric made from high-quality, continuous-filament, nonwoven polyester in the production of its filter cartridges. “This helps create extremely durable filter cartridges that hold up to the rigors of cleaning. However, by their nature of ‘trapping’ contaminant particles, eventually complete cleaning of the filaments is not possible. Since uniformity is key to keeping water sparkling clear, it is important to replace cartridges regularly, ” says John Neely, Global Marketing Manager for Fiberweb.
Filter media type and weight does make a difference. 4 ounce media is recommended for pool applications, lasting anywhere from 3-5 years, while 3 ounce media is more suited to spa applications. Three ounce media in a pool application will have a much shorter life than its 4-ounce counterpart.
As any pool owner knows, filter cartridges, not to mention the rest of the pool package, is quite an investment, but with regular maintenance that investment can pay back many times over in time spent with family and friends enjoying summer around the pool. Happy (and clean) swimming!